Telephone system



Sept. 13, 1927' PORTER TELEPHONE SYSTEM v 2 Sheets-Sheetv l Filed June 25 1925 MTUHWII mm Patented. Sept. 13, c1927.`

uNiTED STAT-*E S;

LEsLrE nron'rEE, onrassfnic, NEW JEEsEY, AssIGNoB To WESTERN ELECTRIC corin PANE', INCORPORATED, on NEW Yo-EK, N. Y.,- A ceaeoEAEiON or NEW YonK.

frELEEHQNEA sYfsfrEivi.v

. This invention relates to telephone signal# ing systems and particularly to.. improvements in` the means for and method .ofjopen ating long distance toll telephone lines..4

' In operating long distance toll .telephone lines the method of handling trailic known as the dispatch method of operation is loften employed. In systems of tliissort cal-ls orig.- Vinating with subscriberswhose lines termi- H) nate at a local central oiice,y are usuallyexf tended over switcliingtrunks to a so-called dispatch otlice having access toy long distance toll lines terminatingat a similar distant dispatch. ot'ce where the connection is conil5 pletedy through .another switching trunkto the local oliice at which the desired subscribers line terminates.. Systems involving this i method of operationliave vbeen .disclosed'as for example,` in Patent No. 1,555,002, granted September 29, 1925, to A. Gray. `When the local oiiices, atl which the calling and called subscribers" lines terminate,y are1 so located that.l long .distance toll-,lines are required as interconnectinglinksI andV dispatch offices are inx'rolvedl for establishing'of con.- nections it `is evident that a IiuinberlfOf` dif; ferent signals,l various` lcommunicationsl between a numberofoperators andthe prepay ration of a number of ticlrets'fcr recording yat the originating dispatchl office thev calls coming in over tollswitching trunks are Vfirst attended' to by a; so-.Called'reportoperator who. communicates overf assignment trunks lwith a so-called dispatch operator,-whov in turn communicates with another dispatch n operator at the distant dispatchofice over a long distance' toll; lilieandfatwhich oliice vsimilar arrangements arev inade to cause the whenY a calling` sulziscriloer4 hangs up hisv re- 50 ceiver.

: lt is, anl object thereforeof this invention yto provide an improvedmethod and means yfor transmitting the disconnectv signalsto the; sadreportand dispatch'operators in an the connections are. involved.;I For example, Y

connection to be completed to a. Wanted sub-- Application ined, June-25, i925. semi N. segui.k

efficient manner and so that such signals will not interfere with conditions of the signaling apparatus used in these circuits for setting up. the connection, signals controlledby such i. signaling apparatus being naturally setto indicate to said operators its conditionat the time theV disconnect signal is given.

To .attain this andother objects of' thei-nventioii, there is provided in accordance with rone feature thereof, a circuit arrangement at the switching trunks and inthe report and dispatch opcrators cord circuits, wherebya disconnect signalincoining through a switch,-

ing trunk is effective vtooperate disconnect 'signals in the report and dispatchoperators cord circuits simultaneously to indicate that the calling subscribeivhas hung. uphis rejcew-cr and that therefore these operators'may break drown the connect-ion by removing their u cord circuits therefrom.

Y Another feature ofthe invention resides in theprovision of such a 'circuitarrangeinent whereby aH disconnect signal in the rep-ort operators. cord circuit is 'controlledk over the sleeve circuitrlbetween the switching trunk and the operators cord circuit, while' the '.disconnect signal in the dispatch operators circuitv isc-ont-rolled' over either 'one of the talking conductors ofthe report operators cordy circuit, the assignment vtrunliinvolved andthe dispatch operators cord circuit.

Another feature of the invention residesri'n means. whereby either alternating or direct current sources. may be employed for sup,-

plyingr the signaling' current o ver either one of the talking conductors to contr-ol the disconnect signal ina dispatch operators cord circuit. ,y ,Y j Y The invention is illustrated in the .accompanying drawings in which Fig. l shows a callin-g subscribers line, al localV automatic oliice diagrammatically represented, a'switching. trunk circuit leading from said local oiliCe and a report operators cord at a dis patch oflice; Fig. 2 shows anassignment trunk circuit and dispatch operators, cord at said .dispatch oflice and a long distance toll line terminating ther-eat, while Fig. 3, illustrates'lthe use of alternating clllIGDtfr 0perationof ,the disconnect signal at Vthe dispatch operations position. A In order to more fully appreciate the sig- .niiicalce Ot the/dispatch'.method oi/ cpera- .in rhandling traine and in p ticular ioo 10 11111110 010.11' 1110 1011111011 01' 11111: 111111111111111 10 1110 151111111111111 1101110011 01101111010 :11111 0111,1- 001.1110121 1111011011 111 :1 0011110011011 001111111011011 0.11 11110 11111510. :1 1211011 110000111111111 11F 1110 V11101110151 0111111031011 111 11101101'11 0111005 111111 110 11111110 10111111011 11.1' 11 11101'0 11011111011 1101400111- 11011 01 1110 111111111111111 101111111' 1111100 111` 1110 111s- 11111011 1111100 1111111111' 1110 00111110' 1111 111111 1'0M 101100 011111011 :1 0011110011011. 110101.11110' 11011' 10 1110 1117111111111 11111 1110111 l110110111111' 001111111' 1111 1110 111100011111011 01 1'110 111011111011 1110111011 1111011` 11 '111 1s 110011111011 1111111 :1 101111' 11101111100 00111100- 11011 1s 110010011 1101110011 11 5111150111101' :111 1110 100111 011100 11110110711 11 111111101011 011100 01101' 11 100g 131101111100 1011 11110 11110111111 111.1011101' 1111:- ].1111011 011100 10 :1 111111110111101.' 111 11 100:11 011100. 1110 01301111011 11'111 110 00 1111101111: T110 1001.11 0100111101'. 1.1511111111' 11 100011111114' 01,101'111i01'-11'011111 pas@ 01011111011 111101011111011 1.0111111111' 10 11 01111 1.1.11 111011110 01' 11 1101101' 10 1110 1.1151301011 0130011- 101' 111y 1110 dispatch 1.1011111011. T110 1115111111011 0110111101' 111 1111'11. 111150011 1110 11012111011 111111111111- 11011 1110110011 10 11 11151301011 0110170101' 111- :1 1110- 111111 011100 01101' :1` 11011-111131' 101111' 11151* 111100 1011 11110. '.11111 11101111111' 111011111011 0110111101' 1'01'01'111: this 111101111011100 011 :1. 1101101. :1111211.13110 :1 1111111- 1101'1'1101'010. 11'1111'11 11111111101' 11110 11110000'. 011 10 1110 111011111011 0110111101" 111 1110. 011.1111111111111' 01111 01 1110 11011 11110 11'1101'0 1111s 111011111011 01.10 '11101' 1'00111'11@y 1110 11111111101' 011 1101.' 1101101' 01 1110 01111. T110 1115111111: 1115111111011 01101111111' 11011' :10111111.11 1,1110 01111 10 1111 :150101111111111 11'111111 1011111110' 10 :1 1'01101'1 01101111010 1.1110111011 111111 110111 1111's- ]1111011 01301111015.' 11010 1110 11111111101' 01.'A 111111 00- 011111111101111 11'11111: 011 111011' 00011001.1111 11011010. T110 1'011111'1' 011010101' 1111100 1110 1101101' '1"1'11111 1110 111011111011 1:11110 111'` 1110 001111110111111' 11111 11111011 011100 :11111 01111110010 0110 111 1101- 101'11 1110011110 10 11 0111110111110' 1'111111; 10111111111' 10 1110 .111001 011100 'F01' 1110 011'101'11111 11]'1 01 1110 011111110 511111113011101'. 11'1111'11 111:11' 1'111 110110 0111101' 11.11 111- :11111111110 0111100111101' 111' 11.1' 11111 111111111111 1110111-A 011. T110 01111111.11' 0111100011101'. 111111'01'01'. 151 1101. 11111;' 111'. 111110 1111110 11111 1f'. 110111 11111101' 1110 1011 11'01 01'1111' 1011011 0110111101'. T110 1'011111'1 111101'- :1101' 11011' 110111100111 1:1111 011101' 01111 0f 1110 001'11 011'0111'1 115011 111111 :111 :101111111111001 11111111 10:111- 1111." 10 1111 111013111011 0110111101' 1111111 :1 11111111 1F; 111.1111011 111 1111's 110111111111 10 .11111101110 111111 1110 S1111S01'1'1101' is 10111111' '1101' 1110 0011110011011. 11111111111111111011' 111111 1110.250 0110111.11011@ 5111111101' 01.1011110110 111'0 1111111111; 11111130 111 111.0 111510111 111011111011 011100. 111.01 10 1110 1'011111'1 01.1111111111' 111' 1111111 011100 00111100@ 11 001'01 10 11 011711101111111' 11'111111 111101 01'11015 111,1 1110 00.11011 0111100111101' :11111 :11111000 11,1111 1'0 111111.11 1111 111s:` 100011101' .'10 0.110 11'111 01111 111111 1911111 101' f1 10110' 111011111011 0011110011011 11'151011 11' 1:1 0011111'. 11111011 1110 1'0- 1101'1 000111101' :11 1110 1115111111 0100 10 0011111101- 0d 111111 1110 :150111111110111 112111111. 11 11111111 :11 1110 1111111111011 01101'0101"0 1100111011 111 111111 01110'1 ].1,11'111011.s0111111111111 111013111011 01101111101' 011 11 11011' 1111011111 1110 111511111011 0110121101' 111 1110 0010111110 11111 011100 111:11 1110 011110,01 0111150111301' 1111s been 0001111111 111111 is 10111151 10 10001110 1110 011.11.

"11'10 1111113111011 1111011111117 :11i 1,110 011011111111111' 0'1"- 1'100 011 1'00011'1'1111 111111 A101110111111100 110011111111 11 101151' 1111111111011. 11111 11110 101' 1110 1.111111110111111 01 1111 011111100111111. :11111 1110 111011111011 01101111.01' :1.1: 1110 011111111111111); 1111100 111111' 01111110010 1111.@ 1111111' 1111111111100 1011 11111' 111111111511 1.110 11.110111111110111 1.1'11111; :11111 1110 1'01101'1 111101'11101"11 1'11111 111:11 11'01'0 11.14011 Y1:01' 1110 011111111011011 1'0 1110 0111111111r 5111150111101' :11111 1111110 1111' 01111111.11 111111110111101'. T110 1'01'101'1` 0110111101' :1011001111011 111111 111111 111011111011 1.1110011111' 111: 111111 111110 100011101'y :1 .1111211111 11'111011 111101110011111 11s' :111 111111011- 111111 111111' 1111-1 1111111' 111S1111100 11111 11110v 1111s; 130011 :0011111011 111111 11'11011 1111' 0111111113T 0111100111101' 11.1151111010. 1110 1'01101'1 111110011101' 1111011110 1.110 011111110 0111100111101' 1111 1, :1 0011110011011 17011115' 1201' 001111110111111. .11,1 1110 111.11110 1:11110 1110 1'01'101'1' 01101111101' 1111001110 1110 111011111011 011010101" 111111: 1110` 01111 11110 1.10011 1111011013011. 3111111111' 0130111- 110110 1:1110 1110.00 1111111111111100111111v :11 1110 111s- 1'11111 11k-.111111011 011100 :11111 111110.11 1111 1110111111011 1111011101' :11' 11111 111.0111111 1111100 10 00.1111'. 11110 11111 ."0 111101'111 1110 1115111111111 0110111101' 111 1110 001011111111111 011100 111111 111101'1 1110 1111111111011 01101111111' 111' 1110 001011111111111' 011100 1"-' 10011111' 11110 111111 :11,20 1111110111 1110 1110111111011 01101111.01' :11: 1110 1110111111 1111100 111 fr0 111101111. T110 111011111011 0110011101' :'11 1110 011011111111111' 011100 11011' 011.1111110 1110 1'1'1101'110110111101' 111111' 11110 1115111111 01111-1' 1S 0011111' :11111 1110 001111110111111 1.2 011101111011 111 1.110 1'01101'1 111101111111'. 1'111' 1'01101'11 0110111101' 11'111 11011' :1s-:1111011110 1101' 101011110110 S01' 11'11'11 11111' 110010111110111'` 13111111; 111111011 is: 111111' 1111111011011 111100111' 101110. 01111011 011111101111111'. 3111111111' 011111111101111 111'0 1111111111' '11111.00 :11' 1110 1110111111 01- 111'0 0.1100111 1111111v 1110 '.'1'1101'1' 111111111101' :11. 1111s 011100 1111.@ 1101101111' 0111111011011 111:1 0111111111; $11111-- .1101'1111'1' 111111111111 10 1110 1111111; 111111111100 1011 11110, 011111111111110 1'01101'1 01101111111' :11 1110 1101115111111 11111 0.1011111100 11'111 11011' 01111111111111011111 11'1111 1110 1': 11011 l@111110111100 111 11111110 .1'111'0 111:11 1110 0011- 110011011 1111s :1011111111Y 110011 0.111111111111011 :11111 11'111 111011 11.1' 1111' 011001111011 01 110111 111 1101' 1'01'11 1'11'1'1111. '10111 1110 0111111111; 111111 01111011 .111110 1'1'1'1110'1' 111113011101'. 111110'1'111111011 1101110011 1111' 011111101111010 11111,' 11011' 111.10 |11:11'0 111111 1111011 1110 11011111111141111011 00:11'1'1' :11111 111" 1.2111111113 1.11111- 1211011101' 11111105.11 1111 111:1 1'01'01'1'01' 11 11111111111111001111 111110011111101 011.1111111 100011011 11.11' 1110 170110011 0110111101' :11111 1110 1 .11111011 01101-1110' :11111 1111 0011110011011 111111' 110 11111011. 1101111.

T0 s001110 11 11101'0 :1001.111110 11111100011111111110; 01j 11 14V 11011 01? 111111 1.11110 111 1'011'1'11'11 1:0 1110 110111111 111111111111111: '1111101101111` 1111111111; 11111011. 11 11011111011 110011111111011 11'111 11011' 110 11111110 111 1110 0001111101111 1111111111' 1111100 111 1110 1115111111011 1.11:- 111'0 111 0111011111110; 11 011,11 11111111011 1110 1.0111011` 111,0; 11'111111. 1110 1'01101'1 01.1011110011 1301'11 011.'- 01111'. 1110 :11'.' 1;;'111110111 10111111 111111 1110 (11.1111113011 0110011130011 001'11 111 1110 1011.11l 1110111111:@` 1011 11110 :1S 111115111111111 1111 1110 1111111111101'.

111'0111 11110 1111010 1101101111 101100111111011 01 1110 0011111111111 01 11` 0011110011011 11i 11'111 |10 .111-1011 111111' 11110 11151 11011011 011 1110 111111' 01 1110 0110011101' 111y 11 c11sp111011 011100 111 110111111117 05111111101111111r af physical connection is tor' he report operator toconnect 'with a' switching-trunk to order up'y the calling subscribers line,

although the callingsubscriber is not rung' atl this time but held undercontrolI oli the report operator. Therefore, when plug V1 of the 'report operators cord: is inserted ini jack 2 of t-he switching trunln'relay 3 is operated" over the tollowing circuit.

winding of relay 8 to 'ground'. Lamp 5 does not operate this time as the resistance oft thesleeve circuit through the Winding of' relay 3 is too highto permit suliici'ent current totlow for the operationl ol the lamp. 'K'As the report operators cord circuit may be ot any l Well-known typel equipped lwith facilities for dialing subscribers lines connected to the cord, it has not been illnstratedin detail. It is suliicientto note that When the report operators cord circuit has'lunctiioned to prepare and' connect the common dialingI equipment thereto, a source of battery will be connectedto the tip conductor of the cord and current from this source causes the operaftion'o'ii' relay 10' inthev switching trunk lthrough the' upper armature and. back con- Y tact olrelay' 10' and the Winding of relay 10 to ground. Relay in operating'pro- 'Vides a locking circuit for itself independent of current on the tip conductor, which circ'uit may be' traced troni battery rat the arma tureand front'contact ot relay 3.' The operation ofgrelayf10 completes the tip and ring .conductors of the' switching trunk to the dialing equipinentl-v in the report operatorscord in one direction and through the automatic:switching equipment connected to this switching trunk` at' the local olllce.` The y transmission et dialing impulses to select the calling subscribers lil-ne may noir be begun` by the' report operator. 4lit should be understood that' automatic selection of; a subscriber may be-'done by means of any automatic equipment rWell-known in the antoinatic switching' art. `lflllhen'the calling 'subscribersl lineA hasv been seized, the battery.y supply on the tipand ring conductors of the switching trunk isreyersed'according tothe Well-'known practice as shown in Patent No. 1,553,337 granted to R." L. Stoliely, September 15,' 1025, and the polarized relay 11 is operated.' A 'The 'circuit oi relay 11 may betraced from the rijngfconrduc'tor at the 4lower left-hand connection to 'repeating` coil v15jthrough polarized relay 11, back contactot1 the inner upper armature of relay 12, vfront contact ol the inner lowerV armature ot relay 10, ring contacts oi jacl; Q and plugl 1,"thencve through the dial (not sli-ouin) in the .report operators cord, tip contactsofpl-ug V1 and jack 2, upper armatureandiront contact of relay 10, and the lower armature an'dfnormal contact of relay '12 to 'the-tip` conductor .ot they switching Battery, lamp 5, sleeve contacts ot plug 1 andi jack 2,

trunk. Thev broken lines in' the tip and, ring conductors of the report operators cord4 leading to plug i1 indicate, among other things, a key by means of which a dial is 'l'iiridged' across thesey conductors in the manner shown in Patent No. 1,448,576` granted? March` 13, 1923, to 1V. B; Stricliler.. The' operation ot' relay 11 causes the operation of relay 12oyer an obvious circuit and relay 12 isl locked:- up to Vbattery at thek lower outer armature and' front contact of relay 10: Relay 121 in operating opens the circuit Jfor' relay 11 and insteady inserts the repeating vcoil 15g between the inward and outward ends ot the switching trunk to insulate the` switching trunk from direct currentsignaling battery. Relay 12 also connects'relay lfacross the voutgoing' tip and ring oi' the switching trunlfzii'or translation of the superlupper inner armature and front contact a path to ground, through the low resistance 111 for the sleeve circuit and lamp V5 so that this klamp will non* light'while relay 3` is still maintained operated.

I VThe next action toward` establishing a: connecti-on Will'be that the report operatorV in.- serts plug 50 into jack 100' of theassignment trunln er circuit Wil-l then be closed ollows: battery, lamp?V 51, sleeve 'contacts of plugO and jack. 100, Winding of relay 101 to ground. This circuit causes the opera'- tionfot relay 101, but lamp 511 is not lighted as the resistance througlrthe Windingv of relay 101'is too high. The operation of relay 1,01 closes an venergizing circuit orrelay 102'. Relay 102 in operating closes a circuit for the soecalledLOK lamps 103 at the dispatchoperators position and multiple .positions thereof andthe lig tingfvof these lamps indicates to this particulardispatch operator that the calling subscriber is ready to be connected up for a long distance connection and to other dispatch operators that this assignn'ient trunk is engaged. This relay also opens at its loWerout-er armature vand bach contact a circuit for relay 105,

which relay `is used in certain disconnect supervisory functions as Will hei'einaiterbe described. i

As previously stated similar operations take place at the distant dispatch oiiice and when the dispatchfoperator at--this'othce receives the information that the called suhseriher haa been securml and is ready to re ceive the call, this dispalcl'i operator :insigni: a long;` dietanee toll line such as loll `tor use iu completing; the connection hetu'eeu these two suhscrihers. lt should he explained at this point that the dispatch tuierator is prorided with a nuinher o'l cords connected through to lone' dietanee toll lines, that is, plugs such as Sie() are connected through at report. operateurs; poeitions to jacks such as 35114 ot long diftance toll lines, sueh Llill). The next action therefore on the part oit the diepateh operator towards einplolxv'ing this lizufticular lone' distance toll line in the connection u'ill he to i .sert plugl 300 ot her cord into jaelt llo olf the engined assignment trunk and a Circuit will then he coinplet'ed as :tollon's: hattery. lainp lower outer contacts ot' ringing; iter lili-i. sleeve coutacts ot' plug;l I300 and jacl; llo., Winding oli relay lll to ground. yllhis circuit causes the operation ot rela)v 'lll lint as the resirftanco through the u'indinu or the` rela); is high lamp 302 is not` operattai al this time. The operation ot relai` lll closes on energizing circuit `tor relay lll) rl this relay in turn ln'ovidcs a` locking circuit lor itself to ground at the upper inner armature and :trout contact ot relay 102. The operation of this relay opens the circuit for the OK lamps 103 at the upper inner armature :uut haelt contact so that these lamps are extin- `ouifhed. This relayr also closes a circuit lor the .so-called guard lainp 115 associated with the jack lOl) at the reportiper-attorel position and this lanip in lighting' informs the report'v operator that a long distance toll line has heen assigned i'or the establishing oli' this connection.

The neat action required is that the dispatch o1 rator rings the calling suhscrilier and to this end sho operates her splitting key illu towards the right to keep the long distance toll line disconnected .troni the as sigulnent trunk during.; ringing; and she also operate.; the ringing; lun' :loll towards the lett. to apph`- ringing current over the tip crniductors to rino; the ealliiu';` suhscriliens line. lfhis ringii urrent applieift over the lolhnringi` circu-, n upper outer right-hand cloffe-:l contacts splitting' l 5' tido, upper lel`t'-hand closed contacts ol ring'- ilu;A key 2.503. tip f 'oi'iductor ol" the dispatch operatore cord. tip terminaley oiE plug Bilt) and fecit lllt tip coiulizel'ruf oi' the a1, u nient' trunk. tip terminalsl olE lach tdt), plut;4 50. tip cout'luetor olthe report operatoi"s cord. tip terminals oli plug l and. joel; il, upper :'.riuature and liront contact ot relay ll). lower armature and Yl'ront Contact; oi rela)7 l2, upper rightfhand Winding1 oli repatine; coil l5, Winding; oit' rela)Y lo to ground. This causes the operation olf rela;T 16 which new applies ri. 4Ning ourrei'it at .its

amano? armatures and front contacts to the calling suhscrihens line. lt' should he noted that the lanip 5 at the report operatois cord is lighted he'liore the ringing current is applied to the switching trunk and is extinguished when relay 16 operates, t s relay 1? u'ill then he released, hu( as soon as the ringingr current is renioved and relay lo releaeet'l, il the. callingl subscriber does not. answer, lan'ip 5 u'ill again he lighted. lgltm'erei, as soon as the calling' subscriber answers the signalingr hattet-y on the switchingl trunk will he reinoi'ed and relayY 1P released, so that lamp 5 u'ill then he extinguished and the report operator thereln int'ornied that. the calling subscriber has answered and the report operator non in the usual manner by associating her telephone set with her cord intel-ins the callingl subscriber that the long distance connection about to he completed.

The calling subscriber will therefore reniain on theV line and the report operator also at. this time informs the dispatch operato r that the callin e' subscriber has answered. '.lo this end the report operator operates her ringing' heb," 52% in the nranner well known in the art to appl)7 ringing' current on the tip conductor.' ot the cord, the assignment trunk and the ('tispatch operators cord to cause the opt-fruition ot relay The circuit for the operation. out this relay is as :follows: hattcry, contacts 5l oli ringingr key 53, tip terminals et plug: and jack 100, tip conductor of the assignment trunk, tip terminals oit jack llt) and plug 300, upper norlnal lett-hand contacts ot ringing key 303, upper Winding oit retardation eoil Slo, lower Winding of rela)T to to ground. llelay 315 provtfles a. locking' eireuit lfor itself from hatterj, through its upper Winding;r and lower arnia.u ture and itront contact to grrountfl at the splitting hey 5506, which is still in operated condition. Relay 315 in operating also closes a cireuit 'for the so called ready with lanip 31.8 as follows: battery, laulp 318, upper armature and Airont, contact ot relay 315 to ground. The lighting ot this lalnp indicates to the dispatch operator that the report op erator has reeeired iutoru'uition that the ealling suhecriher is ready :for the long distance connection.

lllhile these operations are taking` place at this dispatch oilice. similar operations have teiten place at the distant disiiiateh o'flice and 'when the two dispatch operators have been intornud each hy the other that the callingr and called suhseriljiers are ready to be eouneeted over the long distance toll. line, the. dispatch operator at this ottico signals the report operator that the oounection may he t'foinpleted. The operations at: this tin'le will he as follows: The dispatch operator operetes her ringingl key 303 to the lelit so that the lower contacts of this ringing le'y' open the allieve erenlt to the assignment trunk lll() lll] and relay 111 ,isr therebyreleased. Theyrelease ofr relay lllcloses a circuit for relay 118, troni battery` at lai'np 51 over the corresponding sleeve circuit vand fthe lower outer arinatureand front-.contact of relay 112 to groundV so ,that this relay now -locls up ,in

fparallel ywith relay 101.` The lampv 51 4in the report. operatorsnordnow lights as the'resistance though the winding of lrelay y118 l,1s llow/as co1npared w1th the resistance through the windingfof relay -10f1 andthe report ope -pletedf^toithe report operator, while the re-` `Sport operator yconnects herf `telephone vset to n @the as'signinent tru-nk kthrough ithe ,dispatch aoperatorls cord' circuit over thev longv distance toll linefand as similar A operations -arewsimul-v -taneously taking ,place at 'thje 1 distant dis- `pati'zh "oilic'ei'except Ithaft 'the vreport operator "atf-ta'his oilice has now connected .thejcalling subscriber through :tothe long distance 'toll "line, the 'report f operator fat this officie. :will lbeiin vlcioInln'unication `with. thel called subscr-ibe'r.'y The report operator iafter making *sure-fthatI-the calledfli'n'e is actually 'connected restores 'ih er itall'ing key not 'shown and the vsplittingkey 52 sov thatfthe calling :and called subscriber #will now `'be connected and con? Iyersati'oninayzbeging u y When fthe subscribers 'fhave' lini'shed -their f co'n'x'fers ation and the c allin g subscriber h angs ff-35 the Vswitching drunk =to'foper-ate frelaykr13 y which,inow' lreducestlie resistance of the sleeve oircuit'to' fthe report foperato'rs V-cord :by #connecting vthe sleeve circuit tov ground through f "the resistance l'111, at ythe upper -'lower arma- V.*turi-Lfand fron-tf Contact.k lThisrelav-also Isinniltaneouslylp ls'istanee 17 ito "the ring sconduct 'of' the yconv`L-E1ieetin"iatfits upper outer afrinaft contact: e, The 'effect of these connections t0 'Y Lgiound fand V'battery is f 4that report iop-- f 'erator and dispatch 'opera-tor aresiinulta'nej{o uslysignaled toinfdicate "that thejcalling up his receivenf batterylis .again 'supplied at nnectsfbatte'ry fthrough `va resubscribe'rzhas hung upr his receiver 1Van d that fthe connection in ay therefore "be taken down. 1T he reduction i'n'r'esistancev ofl the sleevecir cuit causes 'lainp 'jto bef-l-i-ghted 'whilethe cirf'fcuitjfroni :battery throughaesis'tance 17 over- ,the ringfconducto'rs ofthe connection inaybe ,55, tra-ced if as follows: battery, Vre'si'sta'nce "V1-7,V

"'ielay'il', lowerrighthandtw'intliiig of fre# e, Y l i .rent supply .for/operating the ringiynggrelay upper outer V armature andwr t-rontfcontact of niinalsof ack 12 'fand lplugA 1', rin

ringing key 303, lower winding of retardation'coil 316, winding offrelay 320 .to ground. This causes `the operation kof 'relay 320wh'ich causes lamp 302 to be lightedover an obgvious circuit. Thus lamps -5 and 302 `are sinlult-ane-` ously lighted, by the calling'subscriber-hanging vup `his receiver, so ythat the report operator and the dispatch operator, respectively, are Simultaneously iinforined that the connection n'iay be taken down.

It :nowpt-hereport Toperator removes plug 1.1 troni vjack i2, fthe relays -inl the switch-ing trunk will berestored tonorinal position and lsignals A5 and 302 @will be,V extinguished.

vYVhenthe reportv operator Iremoves plug 50 froinyjackvlOO, relays'l10f1wand 102 in theffasf signrnent trunk circuit will be-restoredgand -a ,circuit :for irfelay icoinpleted as follows fbattery, upp er Iouter l armature i and firent contactjofv relay 4112, lower louter armature and *back contact jot relay F1102; winding `of y 1i-1elav 105, interrupter tog1 ound. Interruvpter 120 will thus cause the alternate qpferation rand releaseot relay .lwhichactions l .lao

on the part volzirelay'105-v'vill alternately-close :and-open a jcircuit'throughQlow resistance fingfthis lamp-to 'alternatelygbe lightedzf-a-nd extinguished. This circuit `anayl be traced/as ,follows battery, lamp '302, lower closed convtacts yci? ringing key 303,1sleeveterminalsot l'plug 300 and .jack 110, low Vresistainze 121,

upper ,-ou'ter :armature -anjd bac-k Contact 'of vrelay '102, armature vand backl Contact off 12elayy 105. This z alternate lighting @and extinguishing" oflarnp-g302: is taken thusf as an inldica`tionfb y y the dispatch operator that `the report :operatori-has restored her portion of 3021trorn battery yappli'edto' the ringcond-uc- Vtor 'ofv :the :f connecting, circuits 'by Vthe foperationojffrelay 1153 may also @be accomplished by the ,-applying:o'fbattery to the tip conductor instead Aof the ring conductor, .thus Vallowing vconsiderable --tlexibility in :the choice. of types o-feinterconnecting:cords and trunk Vcircuits 'withtuit having lto, "make lany Vmaterial changes V in lthe':applica-tion of this phase of thei'nvention. VVfTo furtherernphasiaeft-he ll'exibi'lity-"of the invention,fitshould be po'inted'fout-thatgin l.place oli-fthedirect cur- I302, un .f alternating currentsu-pply -anay be used; E ig. "3 i'llustra'tes h ow ,this can ,be acalternating'ly current #responsive 5 relay 320',

cuits' is such that`f-the i operation ofthe signal lil -lli

may he suhstituted, so that this relaiv will respond upon the operation of relay 1? and cause the energization ot lamp 302.

ir'hat is claimed is:

l. In a telephone system suhscrihers` line, means at a dispatch otiice tor extending a connection 'from a subscribers line through said dispatch oliice including` a switching troni; incon'iing` from the suhscrihefs line`r a, report operators cord. an ass'gninent trunl; and a dispatch operators cord connected in series, means tor simultancousliv signaling at the report o-perators cord over the sleeve collductors oit the switching trunh and the report operatoi"s cord and at the dispatch operators cord over the ring conductors ot the switching trunk, the report operators cord, the assignment trunk and the dispatch operatoris cord comprising sources of current and means responsive to the act oi the suhscriber in replacing his receiver for applying currents :from said source to said switching trunk.

2. In a telephone system, subscribers lines, means at a dispatch ottice ior extcnding a connection from a suhscrihefs line through said dispatch otlicc including a switching trunk incoming from the subscribers line, a report operatoi"s cord, an assignment trunk and a dispatch operatos cord connected in series, means i'or simultaneouslg7 signaling at the report operators cord over the sleeve conductors of the switching trunk and the report operators cord and at the dispatch operators cord over one of the talle ing conductors of the switching trunk, the report operato1"s cord, the assignment trunk and the dispatch ope ators cord comprising sources ot current and means responsive to the act of thc subscriber in replacing his re ceiver for applying currents trom said sources to said switching trunk.

3. ,In a telephone system, subscribers lines, means at a dispatch oiiice for extending a connection from a subscribe/fs line through said dispatch oilice including a switching trunk incoming 'from the suhscrihers line, a report operators cord, an assignment; trunk and a dispatch operations cord connected in series, means tor siinnltaneousli7 signaling at the said report ope 1ators cord with direct current signals over the sleeve conductors of the switching trunk and the 'report operators cord and at the dispatch operators cord with currents oi dilllerent character over one ot the talking conductors ot the switching trunk, the report operatorie cord, theas ment trunk and the dispatch operators cord said currents being applied to said circuits in response to means for supplying energy to the said switching trunk responsive to the act oit the subscriber in replacing his receiver on its hook.

4f. In a telephone system, subscribers lines, long dist-ance toll lines, means for extending a connection from a suhscrihers line to a long distance toll line through a dispatch oil'ice including a switchingr trunk incoming from the suhscrihei"s line, a report operators cord7 an assignment trunk, a dispatch opera Lors cord and a long distance toll line con nccted in series, means 'for signaling at the report operatorie; cord responsive to energy incoi'ning over the switching trunk when a auhscrihefs line is seized, means for signall ing at the incoming end of the assignment trunli responsive to the connection of the report operators cord to said assignment trunk, means for discontinuing said signaling at the incoming end of the assignment trunk in response to the connection of a dispatch opcrators cord to said assignment trunln means for signaling at the outgoing end ot the assignment trunk responsive tothe connection of said dispatch operators cord to said assignment trunk, `means at the dispatch operators cord for transmitting ringing signals to the switching trunk, means at a switching trunk responsive to said ringing signals tor transmitting ringing signals over the switching trunk to the connected subscribers line, means at the switching trunk responsive to the removal of energy by said suhscribers line at said switching trunk for discontinuing the signaling at the report 0perators cord, means at the report operators cord tor signaling at the dispatch operators cord, means at the dispatch operators cord :tor signaling at the report operators cord, and means for signaling at the report operators cord and the dispatch operators cord simultaneously in response to the act of the subscriber in replacing his receiver on its hook.

5. In a telephone system, subscribers lines, long distance toll lines, means for extending a connection from a snbscribers line to a long distance toll line through a dispatch oilice including a switching trunk incomin :trom the suhscrihers line, a report operator s cord, an assignment trunk, a dispatch operators cord and a long distance toll line connected in series, means for signaling at the report operators cord responsive to nergy incoming over the switching trunk when a subscriber-s line is seized, means for signailing at the incoming end oi the assignment trunk responsive to the connection of the report operators cord to said assignment trunk, means ior discontinuing said signaling at the incoming end oi the assignment trunk in response to the connection of the dispatch operators cor'd to said assignment trunk, means for signaling at the outgoing end of the assignment trunk responsive to the connection of the dispatch operators cord to said assignment trunk, means at the disigiatch operators cord for transmitting ringing signals to the switching trunk, means at a switching trunk responsive to said ringlli Lely/2,507'

ing signals for transmitting ringing signals over lthe switching trunk to the connected subscribers line, means at the switching trunk responsive to the removal of energy by said subscribers line at said switching trunk for discontinuing the signaling at the report operators cord, means at the report opera.

tors cord for Asignaling at the dispatch operators cord, means at the dispatch operators cord for signaling at the report operatorscor'd, means for signaling at the report operators cord and the dispatch operators cord simultaneously in response to energy incoming over'the switching trunk when the subscriber connected thereto hangs up his receiver, 'means for discontinuing the signal.-

.operators cord from the assignment trunk,

and means for discontinuing the signaling at the dispatch operators cord in response to the 'disconnection of the dispatch operators cord from the assignment trunk.

- In Witness whereof, I hereunto subscribev my name this 23 day of June A. D., 1925.

LESLIE E. PORTER. 

